1. Field of the Invention
The invention generally relates to animal watering valves and, more particularly, relates to animal actuated valves for use by mice, rats, and other relatively small laboratory animals or commercially raised animals.
2. Discussion of the Related Art
Animal actuated watering valves are well known. One such valve is disclosed in U.S. Pat. No. 7,810,787, which issued to Edstrom Industries, Inc. on Oct. 12, 2010 (the Edstrom patent). The valve disclosed in the Edstrom patent employs a housing having an inlet and an outlet connected by an elongated longitudinal bore, a valve located adjacent the inlet, and an elongated actuating lever or valve stem which extends through the bore, which projects out of the outlet, and which, when deflected by an animal, opens the valve to permit the passage of fluid through the valve housing. A shield in the form of a movable elastomeric boot is provided adjacent the outlet to inhibit the animal from stuffing bedding material or other debris into the outlet and thus inhibits the valve from being unintentionally lodged in its open position.
The valve disclosed in the Edstrom patent includes a head on the valve stem which is resiliently biased against a valve seat by an elastomeric diaphragm. The valve seat takes the form of an elastomeric ring against which a downstream surface of the valve stem head abuts. The diaphragm is formed from a unitary elastomeric element including a central web portion and a cylindrical peripheral portion. The web portion has apertures formed therethrough for the passage of fluid, and also has a recess counter-bored into the downstream surface thereof for receiving a head of the valve stem. A downstream end of the outer peripheral portion is clamped in place within the housing, and an upstream, second end engages a shoulder on the valve cap.
The valve disclosed in the Edstrom patent works very well but exhibits some disadvantages. For example, the housing of the valve of the Edstrom patent does not allow for easy disassembly for cleaning or performing maintenance on the valve.
In addition, while the Edstrom patent recognizes the desirability of providing a shield to prevent the animal from stuffing bedding material into the valve, the disclosed movable elastomeric boot is still susceptible to tampering by the animal stuffing bedding therebetween and/or by being torn by the animal's teeth.
The need therefore exists to provide a valve assembly that is easier to assemble, maintain, and clean than existing animal watering valves.
The need additionally has arisen to provide a valve assembly that prevents animals from stuffing bedding material into the valve and leaving the valve in an actuated position.